"You're coming out of the bullpen again tonight," Costas said, using the baseball metaphors they peppered yesterday's announcement with.

"Actually, I don't feel that bad," Costas said of his condition, "and the irony of it is, we've all felt worse than I feel right now and gone into work. ... I've done lots of ball games and events feeling much less than my best, but in this case it's just involuntary. It's an eye infection, and my eyes are so blurry and watery and become so light-sensitive that even in dim light they're constantly tearing up."

Costas' infection began in his left eye and had spread to his right eye by Monday night. The studio lights and makeup were likely exacerbating his condition, and he admitted Tuesday that the infection is interfering with his vision.

"I can't possibly be in the studio, so it's not a case of just saying, 'What the heck, I'll go in not feeling well,'" Costas added, suggesting that the lights were making things worse.